Pickling is the process of chemically removing oxides and scale from the surface of a metal by the action of water solutions or inorganic acids (“pickling solution”). A typical pickling apparatus includes multiple pickle tanks. The pickle tanks are filled with the pickling solution, such that, as the metal being processed is fed through the pickle tanks, the metal is submerged in the pickling solution. The exposure of the metal to the pickling solution is determined by the length of the pickle tank, the rate at which the metal is fed through the pickle tank, and the number of pickle tanks in the assembly.
As the metal, or pickling material, is moved through the tanks, the pickling solution may splash or overflow within a pickle tank. Splashing and overflow can allow the hazardous pickling solution and fumes to escape the tank. Additionally, the materials frequently used to form pickling tanks (e.g., polypropylene) experience significant expansion and contraction from changes in temperature, thereby allowing the pickling solution and fumes to leak from the pickle tank, especially at the seam between the pickle tank and roll tank.
In addition to splashing and leaking pickling solution, traditional pickle line assemblies are open at the top between the pickle tanks and roll tank. After the pickle tank has been moved into position with the roll tank, closure plates are typically attached to the assembly to cover the top opening between the pickle tank and roll tank. The closure plates can reduce the amount of pickling solution escaping the boundaries of the pickling line assembly, and can contain the fumes from the pickling solution. The necessity of closure plates increases assembly and installation time of the pickle line assembly. Furthermore, despite the closure plates, an annular open space remains around the perimeter of the intersection of the pickle tank and the roll tank from which pickling solution and fumes can escape.